GHSA-cwq5-8pvq-j65j

Source

https://github.com/advisories/GHSA-cwq5-8pvq-j65j

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-cwq5-8pvq-j65j/GHSA-cwq5-8pvq-j65j.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-cwq5-8pvq-j65j

Aliases

CVE-2026-33524

Published

2026-04-24T16:25:11Z

Modified

2026-05-05T16:11:46Z

Severity

7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator

Summary

Zserio Runtime: Integer Overflow in BitStreamReader and Unbounded Memory Allocation in Deserialization

Details

Summary

Unbounded Memory Allocation (all platforms)

A crafted payload as small as 4-5 bytes can force memory allocations of up to 16 GB, crashing any process with an OOM error (Denial of Service).

Affected code (C++):

cpp/runtime/src/zserio/Array.h (line 1029) — m_rawArray.reserve(readLength) with unchecked readLength
cpp/runtime/src/zserio/BitStreamReader.h (lines 249, 281) — value.reserve(len) with unchecked len

Affected code (Java):

java/runtime/src/zserio/runtime/array/Array.java (line 271) — rawArray.reset(readSize) → new int[readSize]
java/runtime/src/zserio/runtime/io/ByteArrayBitStreamReader.java (line 245) — new byte[length]

Proof of Concept

Memory Allocation DoS (verified on 64-bit)

Payload	Claimed Size	Allocated	Amplification
4 bytes	100,000,000	762 MB	~200 million x
5 bytes	2,147,483,647	~16 GB	system crash

The full PoC source code and Docker build files are available upon request.

Impact

zserio is the serialization framework underlying the NDS (Navigation Data Standard), used by 43 member companies including Toyota, BMW, Volkswagen, Mercedes-Benz, and others. According to the Eclipse zserio project:

"Zserio serialized data is used in millions of deployments in cars on the road"

Attack vectors include NDS.Live cloud map updates, map data supply chain compromise, and backend data processing pipelines. On 32-bit automotive ECUs, this could affect ADAS functionality.

Suggested Fix

For all runtimes: Validate varsize against stream size

if (claimedSize > remainingBytesInStream) {
    throw error("varsize claims more data than available in stream");
}

Disclosure Timeline

2026-03-08: Reported to Woven by Toyota PSIRT (go-zserio)
2026-03-10: Reported to ndsev/zserio maintainers via GitHub Security Advisory
2026-03-23: Split off overflow vulnerability to own report
90-day coordinated disclosure timeline

A patch for this issue is available at https://github.com/ndsev/zserio/releases/tag/v2.18.1.

Reporter

Ryuji Yasukochi (ryuji.yasu@gmail.com)

Database specific

{
    "cwe_ids":  [
        "CWE-789"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-04-24T16:25:11Z",
    "nvd_published_at":  "2026-04-24T19:17:09Z",
    "severity":  "HIGH"
}

References

Affected packages

Maven / io.github.ndsev:zserio-runtime

Package

Name: io.github.ndsev:zserio-runtime; View open source insights on deps.dev
Purl: pkg:maven/io.github.ndsev/zserio-runtime

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

2.18.1

Affected versions

2.*

2.4.2

2.5.0

2.5.1

2.6.0

2.6.1

2.7.0

2.8.0

2.9.0

2.10.0

2.11.0

2.12.0

2.13.0

2.14.0

2.14.1

2.15.0

2.16.0

2.16.1

2.17.0

2.18.0

Database specific

last_known_affected_version_range

"<= 2.18.0"

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-cwq5-8pvq-j65j/GHSA-cwq5-8pvq-j65j.json"